x402-gated backup/data endpoint on Base, pay $0.02 per request in USDC — no API keys needed.
What it does
lowpaymentfee.com hosts a collection of x402-protocol pay-per-request API endpoints on the Base network, settling payments in USDC. The specific endpoint at `/api/v1/backups/42` is listed under "Premium API Access" and returns an x402 challenge requiring a one-time USDC payment per call. The site advertises a flat $0.02 per request across all its endpoints, with no API keys, no rate limits, and no minimum commitments.
The provider offers endpoints spanning several categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints follow the same x402 payment model on Base using USDC (contract 0x8335…2913).
The probed endpoint (`/api/v1/backups/42`) returned a valid x402 v1 challenge with `maxAmountRequired` of 20000 base units. Since USDC uses 6 decimals, this equals $0.02 — consistent with the site's advertised pricing. The endpoint accepts POST requests and returns `application/json`. Documentation beyond the landing page is extremely sparse; the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail.
Capabilities
Use cases
- —Retrieving backup data on-demand with per-request USDC micropayments
- —Agent-driven data access without pre-registration or API key management
- —Programmatic access to premium content gated behind x402 payment challenges
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Use cases requiring low-cost ($0.02) per-request data retrieval
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who need bulk pricing or subscription discounts
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/backups/42 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages render only a wallet-connect prompt. The purpose of the specific /api/v1/backups/42 endpoint is unclear beyond its title. This is effectively a stub listing.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) contain no usable content — only a 'Connect wallet' prompt.
- —No OpenAPI or schema definition is available for any endpoint.
- —The specific purpose and response format of /api/v1/backups/42 is undocumented; 'Premium API Access' is the only description.
- —The endpoint path suggests a resource-specific backup (ID 42) but no context is given about what data it returns.
Citations
- —Flat pricing of $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/backups/42
- —Provider offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com